“Nanobiotechnology for health-care”
Cytotoxicity of chemotherapeutic drugs 
loaded into a pH-sensitive star-like copolymer

Ponomarenko S.1, Kuziv Yu.1, Sokolova V.2, Virych P.1, Chumachenko V.1, Kutsevol N.1, Prylutskyy Yu.1, Ritter U.3, Epple M.2

1Taras Shevchenko National University of Kyiv, Volodymyrska Str., 64, 01601 Kyiv, Ukraine. E-mail: prylut@ukr.net 
2University of Duisburg-Essen, University Str., 5-7, 45117 Essen, Germany.
3Technical University of Ilmenau, Institute of Chemistry and Biotechnology, Weimarer Str., 25, 98693 Ilmenau, Germany.

The viability of cancer cell line (human transformed cervix epithelial cells, HeLa) was studied using MTT and Live/Dead assays after incubation with a synthesized pH-sensitive star-like copolymer (dextran-graft polyacrylamide in anionic form (D-g-PAAan)) as a nanocarrier for chemotherapeutic drugs (doxorubicin (Dox) and cisplatin (Cis)), as well as their D-g-PAAan+Dox and D-g-PAAan+Cis mixtures, as a function of the concentration. Fourier-transform infrared (FTIR) spectroscopy clearly indicates the complex formation of Cis and Dox with the D-g-PAAan branched copolymer. The size distribution, value of polydispersity index (PDI) and zeta potential for various aqueous systems containing different particles were determined by dynamic light scattering (DLS) technique. The in vitro uptake of D-g-PAAan+Dox particles into cancer cells was demonstrated by confocal laser scanning microscopy (CLSM; Figure). It was found that D-g-PAAan+Dox particles in contrast to Dox alone showed higher toxicity towards cancer cells. This indicates the possibility of further pre-clinical studies of the water-soluble D-g-PAAan+Dox particles on animal tumor models in vivo as a promising anticancer agent. This work was partly supported by the DFG.

Figure. CLSM images of HeLa cells after 24 h (A) and 48 h (B), correspondingly, of incubation with D-g-PAAan+Dox (62.5+2.5 µg mL-1) particles. Arrows indicate the accumulation of particles inside cancer сells. Actin staining (magenta), nuclei (blue) and particles (green). Scale bar 10 µm.